For the purpose of elucidating the nature of the antigenic stimulation that activates cytotoxic lymphocytes in alcoholic hepatitis, we are developing techniques to quantitate and characterize the excess antibody that circulates in alcoholic liver disease. We have combined a new solid phase radioimmunoassay for IgG and IgA with an enzyme-linked immunoassay (ELISA) that permits us to determine the proportion of circulating antibody that is reactive against intestinal bacterial antigens, which are considered to be potential sources of excessive and pathological antigenic stimulation in these conditions. We are also examining the effect of alcohol, in vivo and in vitro, on two important aspects of lymphocyte function, antibody dependent cellular cytotoxicity and natural ("spontaneous") lymphocyte-mediated cytotoxic activity. Preliminary results indicate that relevant concentrations of ethanol (0.1%) very significantly reduce the potency of these two lymphocyte functions.